fn-9.18 Render utilities (ANSI-aware)

fn-9.18 Render utilities (ANSI-aware)

Description

ANSI-aware rendering utilities for terminal width/padding/truncation.

File

src/lib/render.ts

Functions

// Get visible width ignoring ANSI codes
function visibleWidth(text: string): number

// Pad text to exact width (handles ANSI)
function padToWidth(text: string, width: number): string

// Truncate with ellipsis preserving ANSI reset
function truncateToWidth(text: string, width: number, ellipsis?: string): string

// Strip all ANSI codes
function stripAnsi(text: string): string

pi-tui utilities

Check if pi-tui exports these (it likely does). If so, re-export. If not, implement using ANSI regex patterns.

Testing

Unit tests for each function with:

• Plain text
• Text with color codes
• Text with nested styles
• Edge cases (empty, exact width, over width)

Acceptance

• visibleWidth() ignores ANSI escape codes
• padToWidth() pads to exact visible width
• truncateToWidth() adds ellipsis at visible width
• All functions handle empty strings
• Unit tests pass for plain and styled text

Done summary

• Added src/lib/render.ts with ANSI-aware utilities
• Re-exported visibleWidth/truncateToWidth from pi-tui
• Implemented padToWidth and stripAnsi locally
• Full test coverage for plain/styled/edge cases

Evidence

• Commits: 2f4dcd0748500a6e861249674987a8f2fad72c31
• Tests: bun test src/lib/render.test.ts
• PRs: